Multipole circuit breaker with pivotable handle locking member



Feb. 4, 1969 E. P. DESSERT 3,426,164

MULTIPOLE CIRCUIT BREAKER WITH PIVOTABLE HANDLE LOCKING MEMBER Filed April 10, 1967 JEz enfifi Jdwardi? 36550 23 United States Patent M 3,426,164 MULTIPOLE CIRCUIT BREAKER WITH PIVOT- ABLE HANDLE LOCKING MEMBER Edward P. Dessert, Cedar Rapids, Iowa, assignor to Square D Company, Park Ridge, III., a corporation of Michigan Filed 'Apr. 10, 1967, Ser. No. 629,476 U.S. Cl. 200-42 3 Claims Int. Cl. H01h 9/28 ABSTRACT OF THE DISCLOSURE Description of the prior art A multipole circuit breaker constructed by securing together a plurality of separate, single-pole, molded-case cricuit breakers is disclosed in US. Patent No. 2,889,428, to which reference may be had for a description of the like operating mechanisms disposed respectively in the casings of the separate, single-pole circuit breakers.

Former handle locking members for installation in such multipole circuit breakers between adjacent casings of two of the component single-pole circuit breakers were installable at the option of the user, and frequently by the time it was decided to install such a handle locking member in such a multipole circuit breaker already in use, the handle locking member was already misplaced or lost, resulting in a delay in the desired installation. Further, such former handle locking members, while being extensible and retractable after installation, were not pivotable, and consequently the operating handle of each of the componentsingle-pole circuit breakers had to be relatively long and designed to pivot through a relatively large arc of movement in order to be disposed on opposite sides of a padlock-receiving aperture in the handle locking member when respectively located in ON and OFF positions.

Summary of the invention The handle locking member of this invention is factoryinstalled between adjacent casings of two component single-pole circuit breakers making up a multipole circuit breaker, and therefore it cannot be lost, as it could it were furnished separately from the multipole circuit breaker. Further, the handle locking member of this invention is pivotable relatively to the casings of the component single-pole circuit breakers, and consequently each of their operating handles may be relatively short and designed to pivot through a relatively small arc of movement, while still being disposed on opposite sides of a padlock-receiving aperture in the handle locking member when respectively located in ON and OFF positions.

Brief description of the drawing FIG. 1 is a fragmentary perspective view of a two-pole circuit breaker constructed in accordance with the invention and having a handle locking member constructed in accordance with the invention pivotably and extensiblyretractably mounted between the casings of two component single-pole circuit breakers secured together to form the two-pole circuit breaker, the handles of the 3,426,164 Patented Feb. 4, 1969 component circuit breakers being locked in ON position by the extended handle locking member and a padlock received therein;

FIG. 2 is a perspective view of one of the component single-pole circuit breakers forming a part of the two-pole circuit breaker of FIG. 1;

FIG. 3 is a fragmentary sectional view taken generally along the line 33 of FIG. 1, certain portions being omitted;

FIG. 4 is a view similar to FIG. 3, but showing the positions of the parts when the handles are locked in OFF position;

FIG. 5 is a view similar to FIG. 3, but with the representation of the padlock omitted and the handle locking member in a retracted position;

FIG. 6 is a fragmentary sectional view of the two-pole circuit breaker of FIG. 1, taken generally along the line 66 of FIG. 3; and

FIG. 7 is a perspective view of the handle locking member of the two-pole circuit breaker of FIG. 1.

Description of the preferred embodiment FIG. 1 shows a two-pole circuit breaker 10 constructed in accordance with the invention and mounted behind a trim panel 11. The two-pole circuit breaker 10 is constructed by securing together two substantially identical component single-pole circuit breakers 12 and 13 in a manner more fully explained in US. Patent No. 2,889,- 428.

The circuit breakers 12 and 13 are provided respectively with pivotable operating handles 12a and 13a which together are capped by a handle tie cap 14 held on the handles 12a and 13a by a rivet 15 extending through the handles 12a and 13a as best shown in FIG. 6.

Each side of the casing of each of the circuit breakers 12 and 13 is provided with an aperture 17 (FIGS. 3, 4, and 5) normally closed by a plug 18 (FIG. 2). However, when the two circuit breakers 12 and 13 'are fastened together to form the two-pole circuit breaker 10, the plugs 18 are omitted in adjacent sides of the casings of the circuit breakers 12 and 13, in order to accommodate a common trip crossbar 20, more fully disclosed in the abovementioned patent, which extends into the casings of each of the circuit breakers 12 and 13. The circuit breakers 12 and 13 are secured together by a plurality of rivets 21, one of which is shown in FIGS. 3, 4, and 5.

In accordance with the invention, each side of the casing of each of the circuit breakers 12 and 13 is provided with a circular boss 22 and with certain other boss portions 23, 24, and 25 (FIG. 2). 'Further, a generally flat handle locking member 26, best shown in FIG. 7, is trapped between the casings of the circuit breakers 12 and 13 at the time they are secured together, the bosses 22 of adjacent sides of the casings of the circuit breakers 12 and 13 projecting into an elongated slot 26a, as best shown in FIG. 6. The handle looking member 26 is thus pivotably mounted on the bosses 22 and pivotable between the boss portions 24 and 25 of the respective casings of the circuit breakers 12 and 13. Also, the handle locking member 26 is extensible and retractable, due to the elongation of the slot 2611.

A padlock hasp 28 is receivable in a hole 26b in the handle locking member v26 to lock the handle looking member 26 in an extended position in which it interferes with the handle tie cap 14- upon attempted pivotal movement of the operating handles 12a and 13a. FIG. 3 shows the handle locking member 26 and the handle tie cap 14 in their respective positions for locking the operating handles 12a and 13a in ON position, while FIG. 4 shows the handle locking member 26 and the handle tie cap 14 in their respective positions for locking the operating handles 12a and 13a in OFF position. FIG. 5 shows a retracted position of the handle locking member 26, the padlock hasp 28 having been removed. When the handle locking member 26 is retracted, the 'handle tie cap 14 clears the handle locking member 26 and the operating handles 12a and 13a are free to pivot between ON and OFF positions.

It is within the scope of the invention to substitute recesses in the casings of the single-pole circuit breakers 12 and 13 for the bosses 22 and :bosses on the handle locking member 26 for the slot 26a.

1 claim:

1. A multipole circuit breaker comprising a pair of single-pole circuit breakers secured together in side-byside relationship and each having a separate elongated molded case and a pivotable operating handle normally pivotable betwen ON and OFF positions about an axis disposed within the case and coaxial with the pivotal axis of the operating handle of the other single-pole circuit breaker, handle tie means securing outer end portions of the operating handles together for operation of the operating handles as a unit, and a generally flat elongated handle locking member pivotably and extensibly-retractably mounted between the separate cases of the singlepole circuit breakers, the handle locking member being pivotable between two extreme positions, corresponding respectively to the ON and OFF positions of the operating handles, only when the handle locking member is in a retracted position, the handle locking member being extensible longitudinally thereof from said cases only when in an opposite position from the position of the operating handles, the handle locking member having a hole in an outer end portion thereof for receiving a hasp of a padlock when in an extended position to lock the handle locking member in the extended position in which it interferes with the handle tie means upon attempted pivotal movement of the operating handles, and the pivotal axis of the handle locking member and the pivotal axes of the operating handles being located substantially equal distances from an end of one of the cases of the single-pole circuit breakers.

2. A multipole circuit breaker as claimed in claim 1, wherein said handle locking member has an elongated slot and each of the cases of said single-pole circuit breakers has a boss extending into said elongated slot in said handle locking member.

3. A multipole circuit breaker as claimed in claim 1, wherein each of the cases of said single-pole circuit breakers has a pair of spaced boss portions between which said handle locking member is pivotable.

References Cited UNITED STATES PATENTS 3,255,320 6/1966 Norden 200-42 3,288,954 11/1966 Norden 20042 ROBERT K. SCHAEFER, Primary Examiner.

H. J. HOHAUSER, Assistant Examiner. 

